Pesticide and cancer risk, additional health problems by Ray Sahelian, M.D.
January 20 2016


A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests. Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.
   Over the past decade, hundreds, possibly thousands, of schoolchildren in California and other agricultural states have been exposed to farm chemicals linked to sickness, brain damage and birth defects.


Pesticides and Parkinson's disease
People with long-term, low-level exposure have a higher incidence of Parkinson's disease than people who have not been exposed much to these agents. These workers include farmers, ranchers and fishermen. It appears that exposure to pesticides is a risk factor for Parkinson's disease.
     Harvard researchers examined data from a 2001 American Cancer Society survey of 143,325 people. They contacted those people who reported they had been diagnosed with Parkinson's disease. The American Cancer Society was studying cancer risk factors and all the subjects had reported their eating and lifestyle habits and environmental exposures. More than 5,200 men and 2,600 women were exposed to pesticides. After adjusting for age, sex, and other risk factors for Parkinson's disease, the researchers found a 70-percent higher incidence of the disease among people exposed to pesticides than among those who reported no exposure. More men than women said they had been exposed to pesticides and those reporting exposure were more likely to be farmers, ranchers or fishermen. People who had other jobs and who reported pesticide exposure most likely were using the chemicals at home or while gardening, the researchers speculated. Exposure to asbestos, chemicals, acids, solvents, or coal or stone dust was not associated with a higher risk.


Increased cancer risk with exposure
Exposure to the crop herbicide imazethapyr increases the risk for some cancers. Imazethapyr belongs to a group of chemicals called heterocyclic amines and there is a good evidence implicating several heterocyclic amines as cancer causing. Several heterocyclic amine compounds are used in occupational settings, such as use of the crop herbicide imazethapyr among farmers. International Journal of Cancer, March 1, 2009.


Rev Prat. October 2013. Environment and cancer risk. Several environmental factors, defined as pollutants present in air, water or other media, have been shown to be carcinogenic, including residential exposure to asbestos and radon, second-hand tobacco smoke, diesel engine emissions, and arsenic contamination of drinking water. Other factors, such as outdoor air pollution and water chlorination byproducts, are suspected carcinogens. In the case of pesticides and electromagnetic fields, including the use of cell phones, the available evidence does not suggest an increased risk of cancer. Overall, environmental causes of cancer are responsible for a limited proportion of the total burden of cancer in France and other high-income countries.


Pesticides and brain cancer
Agricultural workers with long term exposure have an elevated risk of brain cancer.


Pesticides and Liver Cancer

High blood levels of the pesticide DDT are associated with an elevated risk of liver cancer.


Pesticides and diabetes
Exposure to agricultural pesticides in the first-trimester increases a woman's risk of developing diabetes during pregnancy. Phthalates may increase blood sugar levels.

The following pesticide chemicals are linked to an increased risk of diabetes: chlordane, oxychlordane, trans-nonachlor, DDT, DDE, dieldrin, heptachlor and HCB.

Pesticide in food
J AOAC Int. 2015. New Trends in Pesticide Residue Analysis in Cereals, Nutraceuticals, Baby Foods, and Related Processed Consumer Products. Pesticide residue methods have been developed for a wide variety of food products including cereal-based foods, nutraceuticals and related plant products, and baby foods. These cereal, fruit, vegetable, and plant-based products provide the basis for many processed consumer products. For cereal and nutraceuticals, which are dry sample products, a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method has been used with additional steps to allow wetting of the dry sample matrix and subsequent cleanup using dispersive or cartridge format SPE to reduce matrix effects.

Nasal and respiratory symptoms
When people think about pesticides and health, cancer and birth defects probably come to mind. But research shows pesticide exposure may contribute to a much more common affliction: itchy, runny, stuffy noses. Occupational and Environmental Medicine, November 2009.


DDT Pesticide and Birds

Nearly half a century after DDT was first dumped across acres of North American farmland and three decades after it was banned in the United States and Canada, the toxic pesticide still has damaging effects on local species. Robins exposed to DDT before birth have damage to regions of the brain that enable them to sing and protect territory. Both functions are integral to mating and were more impaired in male robins, potentially leaving them unable to attract females.


Pesticides in Europe

2006 - EU agriculture ministers issued seven-year authorisations for two highly toxic crop pesticides, azinphos-methyl and vinclozolin, overriding objections from environmental groups that said the products should be banned outright. Earlier, the European Commission was forced to tighten up its proposal for authorising eight pesticides after EU-25 national experts said they were so hazardous that the bloc should impose far stricter rules on their use. The two pesticides may be only be used several meters away from water courses. Azinphos-methyl and vinclozolin may not be sprayed from the air or used in home gardening. Operators must wear protective equipment while using the products and cleaning equipment, which may not be handheld.
   Azinphos-methyl is an organophosphate insecticide used on a wide variety of fruits and vegetables, while vinclozolin is a fungicide used on rapeseed, ornamental flower crops and chicory. The other six pesticides -- carbendazim, dinocap, fenarimol, flusilazole, methamidophos and procymidone -- will be submitted to EU ministers for a rubberstamp authorisation if EU ambassadors can agree to the Commission's amended proposal. Environmental and public interest groups say all the eight pesticides pose a threat to human health and the countryside, and insist that they should be banned completely.